/**
  ******************************************************************************
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Copyright (C) Shanghai Eastsoft Microelectronics Co., Ltd. ALL rights reserved.
  *******************************************************************************
  */

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Version history:
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2019-07-17	V1.0.0	AE TEAM


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Demo introduction:
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Bakup bootloader
带备份的bootloader程序实例，此程序仅处理更新过程，下载数据由APP程序负责
该程序将在上电后，自动检测下载数据区是否有程序数据，如果有，则会将下载数据区的数据复制到APP程序区
若下载区无数据，则不做任何动作，直接运行APP程序

空间分配：
0x00000 - 0x7BFFF BOOT程序
0x07C00 - 0x07FFF BOOT_INFO区
0x08000 - 0x43FFF APP程序区
0x44000 - 0x80000 下载数据区

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System clock:
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External HOSC[12MHz] divided by 3, then PLL to 72MHz.

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Pin connection: 
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UART0_TX ---- PB10[GPIO_FUNC_3]
UART0_RX ---- PB11[GPIO_FUNC_3]

Note: UART0 for debug[baudrate->115200]